From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Experimental designs and issues with the Phantom III rear gearbox mounting.
| Identifier | ExFiles\Box 94\1\ scan0257 | |
| Date | 14th December 1935 | |
| Rm{William Robotham - Chief Engineer} x328 BY.{R.W. Bailey - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} E.1/HP.14.12.35. Phantom 3 Rear Gearbox Mounting. We find that the mounting for the rear end of the gearbox instructed for standard on Phantom 3, as shown on G.82818 sheet 1, has been instructed to N. Sch.4463. This scheme which was issued on 17/4/35 was only intended as a quick experiment of a more flabby rubber, not intended for standardisation, and really not suitable, the outer shell being a solid ring of metal, and the rubber and hub itself not being what we should consider adequate for permanent service. Unfortunately N. Sch.4463 was not tried out until after 25.9.35 and the intention of getting a result on which the final design could be based was thereby frustrated. This mounting moreover got on to the last 10,000 miles test where it has given trouble by the inner bush coming away from the rubber due we think to the contraction of the rubber overcoming the adhesion. The original design of gearbox mounting at this point as shown on N.Sch.4373 has never so far as we are aware given trouble, and an alternative type was only produced to introduce more flexibility in the mounting. It has never been clearly stated as the result of experiment what degree of flexibility is required on the tail end, and we should like to have a ruling from the Experimental Department on this point. N.Sch.4373 was of the type in which the rubber bush was inserted but not vulcanised into the housing. We should now prefer to use in any case a rubber vulcanised to its housing. From the result of the vulcanised test it is evident that the temporary experimental N.Sch.4463 is not suitable for standardisation, and if Experimental results show that this thickness of rubber is necessary a further scheme is required which is shown on N.Sch.4712, and in which the inner housing is considerably increased in | ||